Method and means for removing carbon deposits



Patented Nov. 28, 1933 v PATENT OFFICE,

UNITED STATES METHOD AND MEANS FOR REMOVING CARBON DEPOSITS Wheeler G. Lovell and Thomas A. Boyd, Detroit,

Mich., assignors to General Motors Research Corporation, Detroit, Mich., a corporation of Delaware No Drawing. Application August 28, 1929 Serial No. 389,084

7 Claims.

, method of using them is to apply them to carbon coated parts which have been heated preferably to a temperature above 150 F., the optimum conditions for water cooled engines being at approximatelythe boiling point of water. We may also use with terpene hydrocarbons a mixture of benzol and alcohol, or other low boiling varnish remover, which apparently increases the solvent action of these hydrocarbons not only by reducing the viscosity, but also because they are lower boiling and tend to keep the liquid in contact with the carbon in a mild stateof agitation.

As a specific example we may use in each cylinder of an ordinary six cylinder engine 30 c. c. of a mixture comprising by volume 40 parts of carvene, 30 parts benzol and 30 parts of ethyl alcohol. The engine is operated until the temperature of the metal parts of the combustion chamber is at least 150 F. when the mixture is injected or otherwise introduced into the cylinders and the engine stopped. The mixture is permitted to remain in the cylinders for about two hours, more or less, depending upon the na ture of the carbon deposit, during which time the gummy binder is softened :or dissolved. Then the engine is started and the loosened deposit is gradually blown out the exhaust.

When cleaning the parts by hand they may b heated, the solvent applied, and when the binder is softened the deposit may be wiped off.

It is within the scope of the present invention to employ any terpene hydrocarbon which is a varnish remover and to vary the proportions according to the compound used and the specific conditions, and the terpene hydrocarbons may be used alone.

We claim:-

1. The process of removing carbon deposits from the combustion chamber of an internal combustion engine which comprises applying to the carbon deposit a terpene hydrocarbon which is a varnish remover, and removing the carbon deposit.

2. The process of removing carbon deposits from the combustion chamber of an internal combustion engine which comprises heating the coated parts, applying to the carbon deposit carvene, and removing the carbon deposit;

3. The process of removing carbon deposits from the combustion chamber of an internal combustion engine which comprises heating the coated parts to above 150 F., applying to the carbon deposit a terpene hydrocarbon which is a varnish remover, and a low boiling varnish remover, and removing the carbon deposit.

4. The process of removing carbon deposits from the combustion chamber of an internal combustion engine which comprises heating the coated parts to above 150 F., applying to the carbon deposit carvene, benzol and alcohol, and removing the carbon deposit. 1

5. A composition of matter for removing carbon deposits from internal combustion engines comprising carvene, benzol and alcohol.

6. The process of removing carbon deposits from the combustion chamber of an internal combustion engine which comprises applying to the carbon deposit a solvent taken from the group terpinolene, caryophyllene and carvene, and removing the carbon deposit.

7. A composition of matter for removing 'carbon deposits from internal combustion engines comprising one of the group terpinolene, caryophyllene and carvene, and a low boiling varnish remover.

WHEELER G. LOVELL. THOMAS A. BOYD. 

